You might also find something useful at http://bit.ly/webrtcwebaudio. PeerJS is a library oriented to data exchange: http://peerjs.com.

> The lack of integrated extensions in Chrome <

Could you elaborate on this -- do you mean that the permissions available to Chrome extensions are limited?

Yes. Although I was just reading through the extension docs and realized that you do have permission to add context menu items: http://code.google.com/chrome/extensions/contextMenus.html

So yeah, strike the last item from my list - I blame it solely on PasswordMaker.